SANTA ANA, Calif., Jan 9 (Reuters) - Jurors began deliberating on Thursday in the trial of two former California police officers charged in the 2011 beating death of a mentally ill homeless man, an incident that touched off protests and political upheaval in the Los Angeles suburb of Fullerton.

Orange County Superior Court Judge William Froeberg sent the jury out shortly at mid-morning on Thursday, after instructing them on the law in the month-long, high-profile trial of former Fullerton police officers Manuel Ramos and Jay Cicinelli.

The panel deliberated behind closed doors for about 5 hours before leaving for the day without reaching verdicts. They were scheduled to resume deliberations on Monday morning.

Ramos, 39, is charged with second-degree murder and involuntary manslaughter in the case, while Cicinelli, 41, is charged with involuntary manslaughter and use of excessive force.

Prosecutors say the officers approached Kelly Thomas near a bus depot on the night of July 5, 2011, to question him about reports of vandalized cars, then turned what should have been a routine police encounter into a savage beating that killed the unarmed homeless man.

A surveillance camera at the bus station captured the confrontation between six Fullerton police officers and Thomas. The videotape sparked angry protests in Fullerton, some 30 miles southeast of Los Angeles, and resulted in the ouster of three city councilmen in a recall election.

Defense attorneys argued that Thomas, 37, was dangerous and resisted arrest and that the officers responded properly according to their training.

'SEE THESE FISTS?'

During his final summation in the case earlier on Thursday, Orange County District Attorney Tony Rackauckas urged the jury to convict both men, saying, "Good officers don't act in the manner depicted in this case."

He also referred again to a moment captured on video when Ramos is seen strapping gloves on his hands, balling them into fists in Thomas's face and telling Thomas, whom he knew from previous encounters: "You see these fists? They are getting ready to f--- you up."

An attorney for Ramos, John Barnett dismissed that remark as sarcasm during his closing statement on Thursday, telling jurors it wasn't meant to be taken literally.

"Only a defense lawyer could make that up," Rackauckas said. "It's a threat. It's a threat to beat somebody severely."

Ramos, the first police officer in Orange County to be charged with murder, could be sentenced to a maximum of 15 years in prison if he is convicted. Cicinelli faces up to four years behind bars if he is found guilty.

Former Fullerton police officer Thomas Wolfe was indicted on charges of involuntary manslaughter and use of excessive force in the case last September and is awaiting trial. Three other officers involved in the confrontation with Thomas have not been charged.

In 2012, Fullerton's acting chief of police posthumously exonerated Thomas of any wrongdoing in connection with the confrontation, saying he was cleared of any suspicion that he provoked the violent struggle that led to his death.

The city has also agreed to pay $1 million to Thomas's mother in a negotiated settlement of any claims she might have brought in her son's death. Thomas's father filed a separate lawsuit on the one-year anniversary of the beating. (Writing and additional reporting by Dan Whitcomb; Editing by Cynthia Johnston, Bernadette Baum, David Gregorio and Ken Wills)